Cycle synchronizing apparatus



July 12, 1966 A. A. HASSELBLAD ETAL CYCLE SYNCHRONIZING APPARATUS 5 Sheets-Sheet l Filed Oct. 14, 1964 MVETMTOYLU Cflmbrose CH- QJaJJeb/ad @gfdff QI Q-(aJJelacL 7 2.45 ALM dd c @M July l2, 1966 A. A. HASSELBLAD ETAL CYCLE SYNCHRONI Z ING APPARATUS 5 Sheets-Sheet 2 Filed 001,. 14, 1964 vom@ C/Qm b roJe'/laJJe! b/Qol July 12, 1966 A. A. HAssELBLAD ETAL. 3,260,124

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CA-rvomsuk/ July 12, 1966 A. A. HASSELBLAD ETAL CYCLE SYNCHRONIZING APPARATUS 5 Sheets-Sheet 5 Filed OCT'. 14, 1964 l HPI ML AUTO AND START STOP f Ita-Pz JOC velo-rom@ Cfl mbrose CA. CHaJJe )blad Qsfodtr QQJaJseZb/OLGL A7 h, 4J/4 J4 ms.

CAT-romsy/ United States Patent O 3,260,124 CYCLE SYNCHRONIZING APPARATUS Ambrose A. Hasselblad and Walter J. Hasselblad, both Hasselblad Machine Company, 2405 Mason St., Green Bay, Wis.

Filed Det. 14|, 1964, Ser. No. 403,718 4 Claims. (Cl. 74-63) This invention relates generally to machine tools and more specifically to apparatus; for synchronizing the cycles of two cam drums for operating machine elements in timed relation with each other, the drums being independently driven at different average speeds per cycle.

The general object of the pre-sent invention is to utilize one of said drums to reset the other drum automatically for the beginning of each cycle in a novel and relatively simple manner.

A more 4specific object is to arrange the drums in endto-end coaxial relation and mechanically latch the drums together near the end of their respective cycles automatically as an incident to the `rotation of the drums thereby to reset the drum rotating at the slower average speed.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which FIGURE 1 is a fragmentary perspective showing the two cam drums and portions of the associated machine elements.

FIG. 2 is an enlarged perspective view of a workpiece.

FIG. 3 is a side elevational view of the cam drums and associated elements, parts of the view being broken away and shown in section.

FIG. 4 is a fragmentary perspective view of the drive for one of the drums.

FIG. 5 is an enlarged fragmentary cross-sectional view taken substantially along the line 5 5 of FIG. 3.

FIG. 6 is a fragmentary cross-sectional view taken substantially along the line 6 6 of FIG. 5.

FIG. 7 is an enlarged fragmentary cross-sectional view taken substantially along the line 7--7 of FIG. 3.

FIGS. 8 through 10 are developmental views schematically illustrating the relative positions of the two cam drums lat different times in their concurrent cycles.

FIG. 11 is a diagrammatic view of the primary parts of the control circuits for the machine elements.

As shown in the drawings for purposes of illustration, the invention is embodied in the drive mechanism of an auxiliary spindle attachment 10 of an automatic bar machine. The basic elements of the bar machine, illustrated schematically in FIG. l, are the spindle carrie-r 11 rotatably mounted on the machine base for step-by-step indexing of the spindles through successive angularly spaced operating stations numbered 1-6 in FIG. 1, and the main tool slide 12 slidable back and forth along the base toward and away from the spindle carrier in timed relation with the indexing movements of the latter. At each operating station, selected machining operations are performed on the protruding ends of bars gripped in the spindles, the operations being performed in a well known manner by tools mounted on the tool slide and on the machine base around the spindle carrier.

In the last station, a cut-off tool 14 (FIG. 1) mounted on a radially reciprocable tool slide 15 cuts olf the protruding end portion of the bar to separate the nearly completed workpiece from the bar. Then, as the spindle is indexed from the sixth station to the first station, another length of stock is fed outwardly preparatory to the performance of the machining operations at the first station. The feeding is effected by a feed-out mechanism of well known construction operated by a cam groove 16 formed in a cam drum 17 on a shaft 18 3,260,124 Patented July 12, 1966 ice journaled on the machine base and rotated by the main drive motor 19 (FIG. 1l) of the machine. The speed of rotation of the drum is controlled in a well-known manner by a transmission 19a. During the major part of each cycle, the cam drum is turned very slowly through a short arc, for example, an arc of approximately fifteen degrees, and the feed-out mechanism is idle. Then, during indexing portion of the machine cycle, the drum is rotated rapidly through the remaining portion of its cycle, herein, the remainder of one full revolution, and operates the stock feed-out mechanism to feed a length of -bar stock through the spindle as the latter moves into the -lirst station. The feed-out mechanism shown for purposes of illustration is the standard stock feed-out mechanism used on automatic bar machines manufactured by Greenlee Bros. and Co. of Rockford, Illinois.

As shown in FIG. 1, the auxiliary spindle 201 is mounted on a saddle 21 slidable back and forth along a horizontal dovetail way 22 on the tool slide in axial alinement with the main spindle then disposed at the sixth station. As each workpiece 23y is cut off by the tool 14, the auxiliary spindle advances, clamps the free end portion of the workpiece and returns to the left after the cut-off operation is complete. Then an auxiliary tool 24 on another cross-slide 25 performs an additional operation on the workpiece while it is held in the auxiliary spindle. In this instance, the auxiliary tool is a drill mounted on the cross-slide 25 which is reciprocated back and forth in timed relation with the movements of the auxiliary spindle by a pneumatic actuator 2.7 to move the drill back and forth between a retracted position and the active position coaxial with the workpiece between the latter and the spindle carrier as shown in FIG. 1.

After picking up the workpiece 23 and moving to the left to the position shown in FIG. 1, the spindle moves back to the right to carry the workpiece into engagement with the drill thereby to form a hole 28 in the right end of the workpiece as shown in FIG. 2. Then the spindle 20 returns to the left, the auxiliary t-ool is withdrawn from the path of the spindle, the completed workpiece is ejected from the spindle, and the spindle is advanced toward the spindle carrier to pick up the next workpiece cut off at the sixth station.

To reciprocate the saddle 21 and the auxiliary spindle 20 back and forth in the desired manner, a lever 29 is pivoted fbetween its ends at 30 on the machine base above the tool slide 12 with its lower end pivotally connected at 31 to the saddle and its upper end pivotally connected at 32 to one end of a generally horizontal link 33 extending across the top of the tool slide and the spindle carrier 11 to a point generally above the cam drum 17. At this end, the link is pivotally connected, preferably through a safety device 34, to the upper end of a second lever 35 pivoted between its ends at 37 on the machine and carrying a follower roller 38 on its lower end. The roller projects laterally from the lever into a cam groove 39 formed in the peripheral surface of a second cam drum 40 on a drive shaft 41 rotated by a drive motor 42 (FIGS. 4 and l1). As the drum turns, movement of the groove 39 and the roller 38 longitudinally of the drum Arocks the levers 29 and 35 back and forth in unison to reciprocate the saddle 21 and the auxiliary spindle 20.

Thus, the cycle of reciprocation of the spindle 20 is controlled by the longitudinal movement of the cam groove 39 which, of course, is shaped to produce the desired cycle of the auxiliary spindle. The two cam grooves 16 and 39 are shown schematically in FIGS. 8 through l0 where it will be seen that the groove in the auxiliary drum 40 comprises a rapid approach portion 43 for moving the spindle and the workpiece to the right for engagement with the drill 24, a slow-feed drilling portion 44, and a rapid return portion 45 followed by a short dwell portion 47. Then the groove has a second rapid approach portion 48 which moves the auxiliary spindle into position to pick up the next workpiece from the spindle carrier 11, a short dwell portion 49 during which the workpiece is gripped by the spindle, and finally a return portion 50. This is the complete cycle of the auxiliary attachment and herein is completed slightly less than one revolution of the auxiliary drum.

In accordance with the present invention, the cycles of the auxiliary drum 40 are synchronized with the cycles of the main drum 17 in a novel and relatively simple manner that insures the proper timed relation of the respective cycles despite the differing speeds at which the drums are turned during their cycles by their independently operating motors 19 and 42. For this purpose, the main drum is utilized to reset the auxiliary drum automatically at the begining of each of its cycles, disposing the two drums in a preselected and precisely correlated angular relation from which they begin their respective cycles.

To this end, the two drums 17 and 4t) are rotatably mounted on the machine base in end-toend coaxial relation, and opposed abutments 51 and 52 yare formed on the drums to become engaged when the diums are in the angular relation selected for the starting of the two cycles. The slow speed of the main drum is less than the speed at which the auxiliary drum is driven, but the average speed of the main drum per revolution is greater than the speed of rotation of the auxiliary drum. The abutment 51 on the main drum is positioned to pick up the abutment 52 on the auxiliary drum as the main drum rotaates faster than the auxiliary drum, and the latter is driven by a one-Way drive coupling 53 (FIG. 4) which permits the auxiliary drum to overrun its drive motor and rotate freely at the greater speed of the main drum during the rapid portion of its cycle.

At the beginning of the concurrent cycles, the abutments 51 and 52 are in engagement with each other with the main drum abutment trailing the auxiliary drum abutment. The auxiliary drum first advances relative to the main drum at the beginning of the cycles when the main drum is turning at its slow rate and the stock feed-out mechanism is idle. Before the auxiliary drum completes a full revolution, however, the main drum goes into the rapid portion of its cycle (the stock feed-out portion) and overtakes the auxiliary drum. Thus, the abutment 51 overtakes the abutment 52 and, in effect, mechanically couples the two drums together for the remaining portion of the main drum cycle. Accordingly, the main drum advances the auxiliary drum at the rapid speed and in the selected starting relation, as permitted by the one-way coupling 53, until the main drum slows down to begin its next cycle. At this point, the motor 42 immediately becomes effective to rotate the auxiliary drum at a speed lgreater than the slow speed of the main drum, and automatically begins the next cycle of the auxiliary drum in synchronism with the cycle of the main drum.

In this instance, the abutment 52 on the auxiliary drum 40 is formed by a dog or pin (FIGS. 3 through 6) fast on a disk 54 secured to the end of the drum adjacent the main drum 17, this end portion of the auxiliary drum preferably being of reduced diameter. The pin is spaced radially from the axis of rotation of the drums and projects toward the main drum with the free end of the pin adjacent the plane of the end of the main drum. The disk 54 is fastened to the drum by bolts 55 and threaded into the drum through arcuate slots 57 (FIG. 4) in the disk and thus is angularly adjustable relative to the drum. Spaced an equal distance from the axis of rotation of the drums is ya latch 58 having one side surface facing forwardly in the same plane as the pin to form the abutment 51 engageable with the pin as the main drum rotates relative to the auxiliary drum.

Herein, the latch S is a generally U-shaped plate (see FIGS. 3, 5 and 6) having two legs 59 straddling the end of a bar 60 clamped in a fitting 61 bolted at 62 to the body of the main cam drum 17 inside an auxiliary projecting flange 63 on the end of the drum adjacent the auxiliary drum. A pin 64 spanning the legs of the latch and passing through a bore through the bar 60 pivots the latch on the bar, and a torsion spring 65 (FIG. 5) coiled around the pivot pin acts between the latch and the supporting bar to urge the latch into its normal position shown in FIG. 6 in which the crosspiece 67 abuts against one side of the supporting bar. The latch is swingable counterclockwise (FIGS. 3 and 6) out of this normal position against the action of the spring 65 to permit reverse rotation of either drum during set up, but clockwise rotation is blocked by the bar 60.

As shown most clearly in FIG. 4, the auxiliary drum 40 is mounted on one end of the drive shaft 41 which is journaled in suitable bearings (not shown) on the machine base. On the opposite end of the drive shaft is the one-way coupling 53 which herein is an overrunning sprag clutch of well-known construction operable to couple the drive shaft to a coaxial stubshaft 68 in one direction of rotation of the stubshaft, counterclockwise as indicated in FIG. 4, and to permit free overrunning rotation of the drive shaft relative to `the stubshaft. If the drive shaft begins to turn reversely, that is, clockwise, relative to the stubshaft, the clutch immediately becomes engaged and couples the shafts together.

The stubshaft 68 is driven through reduction gearing including a worm wheel 69 on the stubshaft turned by a worm 70 on a shaft 71 driven by the drive motor 42 through a speed-selecting mechanism shown generally at 72 and an endless chain 73 trained around sprocket wheels 74 and 75 on the shaft 71 and on the output shaft 77 of the speed-selecting mechanism. Through the speed-selecting mechanism, the speeds of rotation of the drive shaft 41 and the auxiliary drum 40 are adjustable to produce the desired speeds of rotation 0f the drum and reciprocation of the auxiliary spindle Z0.

In the absence of any resistance to forward rot-ation of the auxiliary drum 40 relative to its drive, the impact between the latch 58 and the pin 52 when the main drum 17 overtakes the auxiliary drum at high speed could result in overtravel of the auxiliary drum relative to the main drum at the beginning of its cycle and thus could throw the drums out of time. In addition, the inertia of the auxiliary spindle at different critical points in its cycle acts through levers 29 and 35 and the link 33 to advance the drum relative to its drive motor. To prevent such overtravel, means is provided for applying a friction drag to the drum of suiiicient magnitude at each critical point to insure that the drum will be advanced only by its motor or by the main drum.

Herein, the drag is applied by means of a friction brake 78 (FIG. 7) comprising a band 79 almost completely encircling a disk 80 fast on and coaxial -with the drive shaft 41 with the two ends 81 of the band spaced apart on one side of the disk and formed with vertically alined holes through which an actuating rod 82 extends. The lower end portion of the rod telescopes into a bore 83 in a block 84 fast on the machine base and the upper porti-on of the rod is pivotally connected to one end of a lever 85 pivoted intermediate its ends on a pin 87 on the base. A compression spring 88 is coiled around the upper end portion of the rod between the upper end of the band and a washer 89 telescoped loosely on the rod below a pin 90.

With this arrangement, lcounterclockwise rocking of the lever 85 moves the rod 82 endwise and downwardly to compress the spring S0 between the washer `and the band thereby pressing the upper band end downwardly and clamping the band around a liner 91 on the brake disk 80. Since the band is anchored to the machine base by the lower end portion of the actuator rod 82 and the block 84, this clamping applies the desired frictional drag to the brake disk, the drive shaft 41, and the auxiliary drum 40.

To actuate the brake 78 at the critical portions of each cycle of the drum 40, cam blocks 92, 93 and 94 are mounted -on the drum and angularly spaced apart thereon in positions such that they engage the right-hand end of the lever 85 at preselected times when the friction drag is needed. Each o=f these blocks is fastened by two screws 95 (FIG. 7) on the right-hand end 97 (FIG. 7) of the drum, and the leading end of each block is formed with a cam surface disposed in the plane of the lever and inclined radially outwardly and rearwardly relative to the direction of drum rotation to engage a roller 98 on one side of the lever as the cam passes the latter. Thus, each cam swings the lever counterclockwise as viewed in FIG. 7 to apply the brake as the cam passes the lever. The Ilength of each period of brake actua-tion depends upon the length of the arcuate outer holding surface of each cam block and the braking pressure applied depends upon the radial height of this outer surface and the resulting amount cf swinging of the actuating lever by the cam.

With these cams mounted directly on and rotating with the auxiliary drum 40, the actuation of the brake 78 is correlated exactly with the cycle of the attachment 10. Herein, the cam 92 is positioned to apply the brake during the resetting period when the, latch 58 is in engagement with the pin 52, yand the cams 93 and 94 are positioned to apply the brake during the two return strokes of the auxiliary spindle 20.

Als-o mounted on the drive shaft 41 are three operating cams 99, 100 and 101 (FIG. 4), two of which operate valves for controlling the auxiliary spindle chuck and the auxiliary tool slide 25 in timed relation with the cycle of the attachment. The cam 99 controls the valve for actuating the chuck to grip and release the workpiece 23 at appropriate times, and the cam 10,0 controls the valve for operating the reciprocating actuator 27 for advancing and retracting the auxiliary tool. The remaining cam 101 operates a switch AML Which cooperates With switches SPD1 and SPD2 in sensing out-of-time conditions and stopping the machine. The operator for switches SPD1 and SPDZ is mounted adjacent the periphery of the main drum 17 and is operated by a cam 102 thereon. The cooperation of these two switches will be described in detail in the description of the control circuit for the machine.

The starting relationship of the two drums 17 and 40 is shown schematically in FIG. 8 from which it will be seen that the crosspiece of the latch S8 is in engagement with the pin 52 on the auxiliary drum and the two drums are in the precise angular relation selected for the start of the concurrent cycles. In this condition of the drums, the main drum begins its slow-speed rotation while the auxiliary drum is advanced at a greater speed by the motor 42 through the activated one-way clutch 53. Accordingly, while the main drum advances approximately 15 degrees to the position illustrated in FIG. 9, the auxiliary drum advances almost 360 degrees. During this arc of rotation, the follower roller 38 and the auxiliary spindle 20 are moved through the various ma chining motions and through the motions necessary to pick up the next workpiece and begin the retracting motion of the auxiliary spindle. y

At this point, the main drum 17 goes into the rapid rotation of its cycle to operate the stock-feed-out mechanism of the machine, turning at a speed sutiiciently high to overtake the auxiliary drum 40 before the latter completes its cycle. Thus, the latch 58 engages the pin 52 as shown in FIG. and the two drums then rotate together, latched together in the desired startaing relationship, until the main drum slows to start its next cycle.

The primary elements of an illustrative electrical control circuit for the auxiliary attachment are shown schematically in FIG. 11, all the elements being shown in deenergized condition. To initiate the operation of the machine, the operator closes a manually operable start switch 102 to complete a circuit across two power lines L1 and L2 through a normally closed stop switch 103 and a relay HP which, when energized, closes its switches HP1 in the circuits of the main drive motor 19 of the bar machine thereby starting the motor. Relay HP also closes its switch HP2 to complete a holding circuit around the start switch through an automatic cycle switch 104 and a stock switch 105 that is closed while the spindles are supplied with bar stock and opens to signal the need for reloading. Closure o-f the start switch also energizes a relay R2 which opens switch R21 in the circuit of a relay BCR. A second switch R22 opens idly in a circuit yincluding a normally deenergized line L3 and a normally open switch LDC.

With the main drive motor 19 running, rotation of the main cam drum 17 is initiated by engaging a clutch (not shown) actuated by moving a hand lever 107 from the full line position shown in FIG. 15 to the broken line position. In addition to engaging the clutch, this lever closes a switch CLM1 in a circuit to a relay TCR which controls the auxiliary drum motor 42. As the main drum rotates, the cam 102 on its periphery engages the follower 108 which closes switches SPD1 and SPDZ in the circuits of two relays AMC and TCR. When the two drums are rotating together in the proper startaing relationship, the cam 101 on the auxiliary drum shaft 41 closes a switch AML to complete the circuit to the relay TCR through simultaneously closed switch SPDZ thereby initiating energization of the auxiliary drive motor 42. If the drums are not in the proper relation, however, switch SPDZ merely closes idly and the main drum continues to rotate until it picks up the auxiliary drum, bringing the cams 101 and 102 into the proper angular relation for simultaneous closure of switches SPDZ and AML.

When energized, relay TCR is held in by a latch 109 and closes its switch TORI to complete the circuit to relay AlMC which closes its switches AMOI to start the auxiliary .drive motor 42 and begin the operation of the auxiliary attachment 10 in synchronism with the main machine. Closure of switch AMCZ completes a circuit through a signal lamp 1:10.

The machine and the attachment operate in unison until the ,supply of bar stock is exhausted las indicated -by opening of the stock switch 105. When this occurs, re- `lays HIP and R2 are deenergized the next time switch SFDG is opened by the cam 102 on the main drum. Closure of switch R21 completes a circuit to relay BCR /which unlatches relay TCR and thus breaks the circuit to relay AMC. The latter deenergizes the auxiliary motor relay AMC and thus stops the moto-r. At the same time, relay ASV is energize-d through line L3, now closed switch R22, and a switch LDC which is closed momentarily once during each revolution of the main drum by a cam 1111 thereon. Relay ASV operates a valve L12 to admit pressure fluid to the head end of a cylinder 1-13, moving the piston 114 therein to the left (FIG. 11) and shifting the clutch lever 107 int-o the full line position in FIG. 111. Thus, the main machine is thrown o/ut of gear an-d stopped so the supply of bar stock can be replenished. Machine operation is resumed simply by throwing the machine back into gear.

If a jam occurs at any time during machine operation, the safety devi-ce 34 senses the resulting force variation at the link 33 and operates switch 1:14 to energize line L3 instead of line L1. This results in the energization of relay ASV the next time switch DDC closes and ythereby operates the cylinder 112 and throws the machine out Iof gear. The safety device 3 4 forms no part of the present invention and thus is shown only generally herein. For details of construction of one such safety device, reference may be had to our copending application Seriail No. 366,056, led May 8, 1964.

From the foregoing, it will be seen that we have provided a novel and simple arrangement for synchronizing the cycles of the two drurns 17 and 40, utilizing the main drum of the bar machine to reset the auxiliary drum automatically at the end of each main drum cycle. Thu-s, the two drums always start their concurrent cycles in synchronism.

We claim as our invention:

l. In a machine tool, the combination of, a base, a first drum rotatably mounted on said base, first drive means for rotating said first drum in one direction through successive cycles each including a irst portion at relatively slow speed and a second portion at substantially greater speed, a second drum rotatably mounted on said base in endtoend coaxial relation with said i-rst drum, second drive means for rotating said second drum in said one direction at a preselected speed faster than said slow speed, less than said greater speed, and less than the average speed per cycle of said rst drum, a one-Way drive coupling between said second drive means and sai-d second drum permitting the latter to overrun said second drive means and rotate at a speed faster than said preselected speed, and opposed abutments on said drurns radially spaced from the axes thereof and engageable with each other in a preselected angular relation of the drurns with the abutment on said first drum trailing the abutment on said second drum thereby to turn the second drum at the speed of said iirst drum in said preselected angular relation at the end of each of said cycles and until said rst drum begins the rst, slow speed portion of the next cycle.

f2. The combination dened in claim 1 further including a selectively operable brake on said base operable when activated to apply a drag to said second drum, and means for activating said brake in predetermined angular positions of said drum to prevent overtraVel thereof.

3. in a machine tool, the combination of, a base, a iirst drum rotatably mounted on said base, rst drive means for rotating said irst drum in -one direction through successive cycles each including a rst portion at a relatively slow speed and a second portion at a substantially greater speed, a second drum rotatably mounted on said base in end-to-end coaxial relation with said rst drum, second drive means for rotating said second drum in said one direction at a preselected speed faster than said slow speed, less than said greater speed, and less than the average speed per cycle of said lirst drum, a one-Way drive coupling between said second drive means and said second drum permitting the latter to overrun said second drive means, and latching means on said drums operable to prevent fonward rotation of said first drum relative to said second drum When said drums are in a preselected angular relation While permitting fonward relative rotation of said second drum whereby said drurns begin each cycle in said preselected angular relation and return to said relation before the end of each cycle.

`4r. `In a machine tool, the combination of, a base, rst and second drums rotatably mounted on said base in end-to-end coaxial relation, means for rotating said drums in the same direction through concurrent cycles and first advancing said second drum relative to said first drum and then advancing said rst drum relative to said second drum to overtake the latter near the end of the concurrent cycles, and opposed abutment surfaces on said drums positioned to become engaged and latch said drums together in a preselected angular relation after said rst drum overtakes said second drum whereby said drums begin said concurrent cycles in said preselected angular relation.

No references cited.

MILTON KAUFMAN, Primary Examiner.

D. H. THIEL, Assistant Examiner. 

4. IN A MACHINE TOOL, THE COMBINATION OF, A BASE, FIRST AND SECOND DRUMS ROTATABLY MOUNTED ON SAID BASE IN END-TO-END COAXIAL RELATION, MEANS FOR ROTATING SAID DRUMS IN THE SAME DIRECTION THROUGH CONCURRENT CYCLES AND FIRST ADVANCING SAID SECOND DRUM RELATIVE TO SAID FIRST DRUM AND THEN ADVANCING SAID FIRST DRUM RELATIVE TO SAID SECOND DRUM TO OVERTAKE THE LATTER NEAR THE END OF THE CONCURRENT CYCLES, AND OPPOSED ABUTMENT SURFACES ON SAID DRUMS POSITIONED TO BECOME ENGAGED AND LATCH SAID DRUMS TOGETHER IN A PRESELECTED ANGULAR RELATION AFTER SAID FIRST DRUM OVERTAKES SAID SECOND DRUM WHEREBY SAID DRUMS BEING SAID CONCURRENT CYCLES IN SAID PRESELECTED ANGULAR RELATION. 